In recent years, the proliferation of digital photography has provided consumers with a variety of options to store captured images. These options include various “soft copy” methods involving memory cards, memory sticks, CD's, DVD's, hard drives, on-line storage etc. These “soft-copy” options, while providing the environmental benefit of eliminating the paper, ink or dye, and other chemicals required for “hard-copy” output, are potentially less secure for long term storage due to media format obsolescence, storage media physical or chemical breakdown, and on-line storage companies disappearing. A variety of options exist for customers to print digital images, including conventional silver halide processing, ink-jet, thermal dye transfer, and electrophotographic methods. These “hard-copy” methods are capable of providing printed output which can last for many decades. Although customers can make such “hard-copy” prints at home, modern retail outlets provide kiosks and order-terminals where both prints and additional services can be requested and provided. Similar services are also available from on-line companies such as Kodak Gallery. An increasingly popular service provides photo-albums or photo-books with collections of images associated with a specific event, such as a vacation, family gathering, school function etc. The photo-books are composed of printed images produced by any one of the printing methodologies described above.
Photo-books can be constructed in various formats. For example, single sheets of printed material bearing an image on one side of the material can be bound together using any one or a combination of binder clips, staples, adhesive, stitching, ring binders etc. Such photo-books are generally less preferred as each printed page of the book will face a blank page, i.e. the non-printed backside of a printed image. This disadvantage can be eliminated by adhering together sheets of single-side printed media to produce a double-sided album page as disclosed in U.S. Pat. Nos. 5,791,692, 5,957,502, 6,004,061 and 7,047,683. U.S. Pat. No. 6,742,809 describes a strip of images folded in accordion manner such that each pair of adjacent images forms two sides of a page, the accordion folds being adhered together on the inside. Photo-books produced by adhering two imaged prints together are typically thicker than single-sided sheet products, and this can result in a heavy and bulky product when the photo-book contains a large number of pages.
Duplex printers, which print on both sides of an imaging material, are known in the art. Typically these printers are of the electrophotographic type. Using these printers, photo-books can be constructed from the duplex sheets using any of the methods described above. Thermal transfer printing is known to produce higher quality images than conventional electrophotographic imaging, and would be the preferred printing method for high-quality photobooks. Duplex thermal transfer printers are disclosed in U.S. Pat. Nos. 5,550,572, 5,677,722 and 7,486,421. These patents do not disclose any method for using the duplex output from these printers to produce photo-books.
There is need to produce high quality photo-books from duplex printed sheets. There is also a need to manufacture a binding clip for such photo-books that holds the printed sheets securely in a cost-effective manner.